The wireless distribution of broadband signals within a building is becoming commonplace. Wi-Fi is now the most common way people access the Internet. Smart phones compliant with 3G and 4G standards are commonly used inside buildings. Personal computers, laptop computers, cellular phones, tablet computers, PDAs and other portable devices are typically configured to receive a wireless broadband signal. In addition, televisions, DVD players, Blu-ray disc players, smart thermostats, printers, copiers and many other digitally enabled home or business appliances are configured for wireless network access. To meet the needs of these and similar devices, many buildings now include a wireless access point (WAP), base station or repeater connected to a local or external network to send and receive data or communication signals to and from wireless devices within or near the building.
Prior to the advent of local wireless networks, a home or business owner was required to run cables through walls and ceilings to deliver network access to any network enabled devices within the building. Now, a building owner may have wired access to the Internet, a LAN or another network at one specific location within a building and simply install a wireless router or other type of WAP to more easily extend the network to end-user devices. A WAP is built to support a standard for sending and receiving data using radio frequencies. The standards and the designated transmission frequencies used are defined by the IEEE. Many wireless access points use the 802.11a/b/g/n, or 802.11ac/ad standard.
Other types of networks, cellular telephone networks for example, feature a wireless signal originating outside of the building. The walls, floors and other structures of the building can attenuate or degrade the original wireless signal sufficiently to cause access problems for cellular telephone users within a building. Thus, femtocells, wireless repeater devices, or other wireless network elements can be installed within a building to transmit certain wireless signal locally. Many of these wireless network elements use LTE, or LTE Advanced standards
One problem with the transmission of wireless broadband signals within a building is difficulty obtaining a sufficiently strong communication channel between the WAP or repeater and various receiving devices. For example, the popular Wi-Fi standard defined in IEEE 802.11b is a low powered solution (less than 1 W) having a range of no more than 300 feet from the transmitter. The closer a receiving device is to the transmitter the better chance the receiver will have of connecting and typically the faster the Wi-Fi uplink/downlink performance will be. Connectivity and signal strength problems can be exacerbated by the walls, floors, ceilings and other surfaces or barriers present in a typical building which can cause signal attenuation and reflection.
One solution to this problem is to provide duplicate WAPs distributed throughout a building with each WAP directly connected to the wired network or repeater. This solution however involves the cost and inconvenience of duplicate WAPs and additional cabling. Another solution is the use of wireless range extenders or signal boosters
Another solution to the problem of insufficiently reliable communication between a WAP and various receiving devices is based upon advanced antenna technology. For example, multiple input/multiple output (MIMO) is a wireless technology which employs multiple intelligent radio antennas to improve transmission speed and the quality of wireless network transmissions over longer distances than might otherwise be possible. Enhanced antenna technology may certainly improve the reliability, speed and range of wireless broadband communication within a building. Nonetheless, any wireless system will at some point be limited by the distance between the WAP and wireless devices, which limitations are exacerbated by the walls, floors, ceilings and other surfaces or structures always present in a building.
U.S. Pat. No. 6,980,768 teaches the use of a building ventilation system as a waveguide to enhance the distribution of a spread spectrum signal within a building, in particular a code division multiple access (CDMA) telecommunications signal. The U.S. Pat. No. 6,980,768 describes how the ducts of a conventional ventilation system can operate as waveguides. Bends, kinks, rough surfaces, splits, and variations in duct size or configuration will inevitably cause fading in any RF signal transmitted through a duct waveguide. The spread spectrum nature of the signal described in the U.S. Pat. No. 6,980,768 provides little opportunity for transmission optimization within a ventilation system. Hence, there is a need for solutions that can overcome some or all of the technical hurdles identified above to allow the effective distribution and optimization of the distribution of broadband wireless signals in a building.